Cruise Control problems of the 2006 Toyota Scion Xa

I was on the highway and using cruise control. When I tried to turn it off, the light went off, but the vehicle continued to hold speed. The I tried to engage the cruise control and decelerate/accelerate, but the only effect was accelerating up to 80mph. Stepping on the brakes only slowed the vehicle down and didn't disengage the cruise control. I tried to shift the gears to neutral and still no effect except the engine revving to the red line. So I floored the brakes and could only slow the vehicle down to 20mph. Worried about what else may happen, I exited the highway and turned on to a street. Seeing no other options, I chose to just turn the engine off. At that point the power brakes stopped working and the car was still rolling. So I shifted the gear to park and we stopped abruptly.

The contact owns a 2006 Toyota Scion Xa. While driving 5 mph, the vehicle accelerated to 15 mph. The brake pedal was depressed; however, the vehicle would not stop and crashed into a tree. The vehicle was restarted and the throttle was fully engaged. The vehicle was towed to the dealer and they stated that the failure was due to the aftermarket rostra cruise control switch. The failure previously occurred without a crash and the dealer previously recommended that the cruise control be disconnected. The cruise control was not disconnected because the dealer stated that the failure had been repaired. The failure mileage was 13,200 and current mileage was 13,200. Updated 3/4/08 updated 03/04/08.